> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ionicfi.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Download an invoice PDF

> Renders the invoice and its recorded payments as a PDF. This endpoint
requires a direct Account secret key and does not accept `Ionic-Account`.




## OpenAPI

````yaml /openapi/invoices.yaml get /invoices/{id}/pdf
openapi: 3.0.3
info:
  title: Ionic Invoices API
  version: '2026-05-30'
  description: |
    Invoices and invoice items.

    An invoice item is a pending charge recorded against a customer. When an
    invoice is created for that customer, every pending item in the invoice
    currency is drained onto the new draft as a line. A draft can be edited
    freely; finalizing it assigns a gapless, per-merchant/mode sequential number
    (for example `INV-000001`), applies tax, freezes the lines, and opens the
    invoice. Drafts carry no number, so an abandoned draft never consumes one
    and the finalized sequence is always contiguous.

    All monetary amounts are integers in the currency's minor unit (for example
    cents for USD). Timestamps are Unix epoch seconds. Identifiers are opaque,
    prefixed strings: invoices are `inv_…`, invoice items `ii_…`, and invoice
    lines `il_…`.

    Authentication uses a merchant secret key as a bearer token. Read endpoints
    require the `invoices:read` permission; write endpoints require
    `invoices:write`. The mode of the key (test or live) scopes which invoices
    and invoice items it can see, mutate, and drain. Live invoice numbers use
    `INV-000001` style labels; test invoice numbers use `TEST-INV-000001`.
    Mutating endpoints accept an optional `Idempotency-Key` header.

    Errors are returned as `{ "error": { "code": "...", "message": "..." } }`.
    A malformed path identifier returns 400. Concurrent updates are retried
    automatically; if they still conflict, the API returns 409 and the request
    can be retried.
servers:
  - url: '{baseUrl}/v1'
    variables:
      baseUrl:
        default: https://api.ionicfi.com
        description: API base URL for your environment.
security:
  - secretKey: []
tags:
  - name: Invoices
    description: Create, finalize, and manage invoices.
  - name: Invoice Items
    description: Pending charges that drain onto a customer's next invoice.
paths:
  /invoices/{id}/pdf:
    parameters:
      - $ref: '#/components/parameters/InvoiceId'
    get:
      tags:
        - Invoices
      summary: Download an invoice PDF
      description: >
        Renders the invoice and its recorded payments as a PDF. This endpoint

        requires a direct Account secret key and does not accept
        `Ionic-Account`.
      operationId: invoices_download_pdf
      responses:
        '200':
          description: The rendered invoice PDF.
          headers:
            Content-Disposition:
              description: Inline filename derived from the invoice number.
              schema:
                type: string
          content:
            application/pdf:
              schema:
                type: string
                format: binary
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '404':
          $ref: '#/components/responses/InvoiceNotFound'
        '429':
          $ref: '#/components/responses/RateLimited'
        '500':
          $ref: '#/components/responses/InternalError'
      security:
        - secretKey:
            - invoices:read
components:
  parameters:
    InvoiceId:
      name: id
      in: path
      required: true
      description: The invoice id (`inv_…`).
      schema:
        type: string
  responses:
    BadRequest:
      description: The request was malformed or failed validation.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error:
              code: INVALID_DATA
              message: invalid currency
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    Forbidden:
      description: The key lacks the required permission, or the merchant is not active.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    InvoiceNotFound:
      description: No invoice with that id is visible to this key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error:
              code: INVOICE_NOT_FOUND
              message: invoice not found
    RateLimited:
      description: Too many requests. Honour the `Retry-After` header before retrying.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    InternalError:
      description: |
        The API could not return a successful response. For a mutating request,
        retrieve the resource before retrying because the operation may have
        completed.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  schemas:
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            code:
              type: string
              description: A stable, machine-readable error code.
            message:
              type: string
  securitySchemes:
    secretKey:
      type: http
      scheme: bearer
      description: 'A merchant secret key (`sk_…`) sent as `Authorization: Bearer <key>`.'

````